There are different bin/dev being generated by cssbundling-rails and jsbundling-rails

See rails/jsbundling-rails#174

> dev: Use an affirmative conditional
>
> ...and avoid regex in match.
>
> (Try a gem list ails vs a gem list --exact ails to see what I mean.)

The `css:install:shared` task serves only as a prerequisite for the
other installer tasks; it should not be run on its own (nor listed with
`rake --tasks`).  By replacing this task with corresponding calls to
Thor's `apply` method, we avoid the overhead of running
`bin/rails app:template` (and `bundle install`) multiple times.

See discussion in issue #92 #92

Rails 7.1 included a [change][1] to allow using importmaps along with
all cssbundling options. However, the Bootstrap installer was never
updated to take this new default into effect (and is currently broken
because of this).

This commit adds the additional configuration required to use the
Bootstrap npm package with importmaps so that "rails new" generates an
application that runs without errors.

[1]: rails/rails@84458a8

* Simplify build tool selection for bun / yarn

Simplifying ahead of introducing NPM as a build tool.

* Support for NPM

* Support PNPM

Fixed #137